This is the law about beast and bird and every living creature that moves through the waters and every creature that swarms on the ground, to make a distinction between the unclean and the clean and between the living creature that may be eaten and the living creature that may not be eaten.
A couple of years ago, I had the privilege of teaching a humanities class to ninth and tenth graders and formed a strong bond with a student named John. John was a strong-minded, big-hearted guy whose family had recently begun acclimating Old Testament kosher laws back into their spiritual discipline. At one point during a class discussion, after I made a comment relating to the covenant of grace eclipsing the covenant of law, John interrupted the lecture with a well-articulated rebuttal: “But God doesn’t change Who He is, Mr. Seth. He wouldn’t tell us one day, ‘Don’t eat that—it’s unholy,’ and then tell us the next day, ‘Okay, eat that—it’s good now.” But when I graciously brought up Acts 10 to the discussion, he hadn’t yet read of Peter’s vision, nor even of the Jerusalem council in Acts 15, nor of Paul’s confrontation of Peter in Galatians; so while his conviction for God’s immutable character was honorable and true, his arguments for it fell short.
In brief, God hasn’t changed His appetites over the years. That is, He hasn’t started preferring the taste of bacon to the taste of beef, because He doesn’t eat any of it! He doesn’t hunger like we do. We’re the physical beings in a physical world with physical limitations needing physical signs—not Him. That’s what these laws are about. God enables these pilgrims to stand out amidst their idolatrous neighbors by giving them physical, sacramental ways to express their uniqueness. For this reason Nazarites like Samson made a vow not to cut their hair or drink wine and Jewish males were circumcised on the eighth day. That’s what changes between Leviticus 11 and Acts 10. Not the immutable character of God Himself, but the mutable, practicable symbolism for us.
Christ taught us in Luke 5 that we can’t put new wine in old wine skins, lest they burst, which serves as a good analogy for Leviticus 11. It’s an old wineskin, good for its time, but bursting under the immeasurable freshness of Christ’s Passion.